This study is intended to assess the safety and efficacy of administering MK-0677 to GHD children who have been previously treated with rhGH. The primary endpoint of the study will be dose ranging information for subsequent trials based on absolute growth velocity after 6 months of treatment, supported by increases in mean percent change in IGF-I concentrations compared to baseline. The trial will also demonstrate whether the response to a bolus dose of MK-0677 predicts efficacy as determined by by growth response. We are in the first few weeks of studying our first subject.